U.S. patent number 6,646,101 [Application Number 10/291,097] was granted by the patent office on 2003-11-11 for use of copolycarbonates.
This patent grant is currently assigned to Bayer Aktiengesellschaft. Invention is credited to Klaus Horn, Annett Konig, Silke Kratschmer, Steffen Kuhling, Rolf Wehrmann.
United States Patent |
6,646,101 |
Kratschmer , et al. |
November 11, 2003 |
Use of copolycarbonates
Abstract
The present invention provides the use of impact resistant,
stress cracking resistant copolycarbonates with particularly good
low temperature properties for applications in which particularly
good low temperature properties are required, e.g., for automobile
construction or external applications, and new copolycarbonates
themselves.
Inventors: |
Kratschmer; Silke (Krefeld,
DE), Horn; Klaus (Dormagen, DE), Konig;
Annett (Krefeld, DE), Wehrmann; Rolf (Krefeld,
DE), Kuhling; Steffen (Meerbusch, DE) |
Assignee: |
Bayer Aktiengesellschaft
(Leverkusen, DE)
|
Family
ID: |
7657561 |
Appl.
No.: |
10/291,097 |
Filed: |
November 8, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
962168 |
Sep 24, 2001 |
|
|
|
|
Foreign Application Priority Data
|
|
|
|
|
Sep 26, 2000 [DE] |
|
|
100 47 483 |
|
Current U.S.
Class: |
528/196; 359/361;
428/412; 528/198 |
Current CPC
Class: |
C08L
69/00 (20130101); C08G 64/06 (20130101); C08L
51/04 (20130101); C08L 51/04 (20130101); C08L
2666/14 (20130101); C08L 69/00 (20130101); C08L
51/00 (20130101); Y10T 428/31507 (20150401) |
Current International
Class: |
C08L
69/00 (20060101); C08G 64/00 (20060101); C08G
64/06 (20060101); C08L 51/00 (20060101); C08L
51/04 (20060101); C08G 064/00 () |
Field of
Search: |
;528/196,198
;359/109,361 ;428/412 ;296/37.1 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
5401826 |
March 1995 |
Sakashita et al. |
5470938 |
November 1995 |
Sakashita et al. |
5532324 |
July 1996 |
Sakashita et al. |
|
Foreign Patent Documents
Primary Examiner: Boykin; Terressa M.
Attorney, Agent or Firm: Gil; Joseph C. Preis; Aron
Parent Case Text
This application is a divisional of U.S. Ser. No. 09/962,168, filed
Sep. 24, 2001.
Claims
What is claimed is:
1. A process of using a thermoplastic molding composition that
contains a copolycarbonate comprising 34 to 26 mole % of residues
of compounds corresponding to formula (I), ##STR4## wherein R.sup.1
to R.sup.4 independently of one another, represent H, C.sub.1
-C.sub.4 -alkyl, phenyl, substituted phenyl or halogen, and 56 to
74 mole % of residues of compounds corresponding to formula (II)
##STR5## wherein R.sup.5 to R.sup.8 independently of one another,
are H, CH.sub.3, Cl or Br, and X is C.sub.1 -C.sub.5 -alkylene,
C.sub.2 -C.sub.5 -alkylidene, C.sub.5 -C.sub.6 -cycloalkylene,
C.sub.5 -C.sub.10 -cycloalkylidene, as monomers, wherein the total
of said mole % of residues of monomers corresponding to formula (I)
and formula (II) is equal to 100 mole % the process comprising
molding an article and subjecting the article to temperature lower
than 0.degree. C..
2. The process of claim 1 wherein the article is a film.
3. The process of claim 1 wherein the copolycarbonate comprise 30
mole % of residues of compounds corresponding to formula (I).
4. The process of claim 1 wherein the compound of formula (I) is
4,4'-dihydroxydiphenyl.
5. The process of claim 1 wherein said copolycarbonates comprise 30
mole % of residues of 4,4'-dihydroxydiphenyl.
Description
The present invention provides the use of impact resistant, stress
cracking resistant copolycarbonates with particularly good low
temperature properties for applications in which particularly good
low temperature properties and good impact behavior after heat
aging are required, e.g., for automobile construction or external
applications, and new copolycarbonates themselves.
For automobile construction and other external applications there
has long been a search for polycarbonates which are as resistant as
possible to chemicals and preferably transparent and which, on the
one hand, are resistant to low temperatures and on the other hand
have good aging stability. The object was, therefore, to find a
transparent polycarbonate which, on the one hand, exhibits improved
low temperature impact strength compared with polycarbonate
composed of pure 2,2-bis(4-hydroxyphenyl)propane and, on the other
hand, has increased aging stability, with improved stress cracking
behaviour.
Polycarbonates typically loose their notched impact strength and
become brittle at low temperatures. Additionally polycarbonates
display, after storage at temperatures below the glass transition
temperature, an ageing effect which is dependent on the period of
storage and the temperature and as a result of which the high
energy level of the notched impact strength is considerably
decreased (Bottenbruch et al., Engineering Thermoplastics
Polycarbonates, Polyacetals, Polyesters, Cellulose Esters, Carl
Hanser Verlag, Munich, Vienna, N.Y., 1996, p. 183 et seq.).
Copolycarbonates based on 4,4'-dihydroxydiphenyl and
2,2-bis(4-hydroxyphenyl)propane are already known from JP 5117382
and have been described in EP-A1 0 544 407, U.S. Pat. No.
5,470,938, U.S. Pat. No. 5,532,324 and U.S. Pat. No. 5,401,826 as
being particularly chemical resistant, heat resistant and flame
resistant whilst having, compared with commercial polycarbonate of
pure bisphenol, the same mechanical properties and transparency.
There is no indication whatsoever in the prior art, however, that
these copolycarbonates have particularly good low temperature
properties or a particularly good impact behavior after heat
aging.
The problem therefore consisted in obtaining an polycarbonate with
high transparency which on the one hand possesses improved low
temperature properties, i.e. good notched impact strength even at
low temperatures, especially compared to usual polycarbonate made
of 2,2-bis(4-hydroxyphenyl)propane, and on the other hand shows an
improved ageing behaviour when tempered below glass temperature
besides enhanced environmental stress cracking.
It has now surprisingly been found that the copolycarbonate
according to the invention does not exhibit any ageing effects upon
storage at temperatures below the glass transition temperature, so
that the high energy level of the notched impact strength is
maintained.
These unexpected ageing properties of the copolycarbonate according
to the invention are of major importance for practical use. Many
uses are subject to continuously changing thermal conditions. The
copolycarbonate according to the invention thus represents a
material which has very high notched impact strength at low
temperatures and which does not however lose this property as a
result of storage at high temperatures due to ageing effects.
The present invention relates, therefore, to the use of
copolycarbonates which are composed of 0.1 mole % to 46 mole %,
preferably 11 mole % to 34 mole % and particularly 26 mole % to 34
mole % of compounds corresponding to formula (I) ##STR1##
wherein R.sup.1 to R.sup.4 independently of one another, stand for
H, C.sub.1 -C.sub.4 -alkyl, phenyl, substituted phenyl or halogen,
preferably for H, C.sub.1 -C.sub.4 -alkyl or halogen and
particularly preferably all stand for the same radical,
particularly for H or tert.-butyl,
and complementary amounts, that is, 99.9 mole % to 54 mole %,
preferably 89 mole % to 66 mole % and particularly 74 mole % to 66
mole % of compounds corresponding to formula (II) ##STR2##
wherein R.sup.5 to R.sup.8 independently of one another, are H,
CH.sub.3, Cl or Br, and X is C.sub.1 -C.sub.5 -alkylene, C.sub.2
-C.sub.5 -alkylidene, C.sub.5 -C.sub.6 -cycloalkylene, C.sub.5
-C.sub.10 -cycloalkylidene, as monomers, as materials in areas in
which particularly good low temperature properties and good aging
stability are required.
More particularly preferred copolycarbonates and themselves the
subject of the invention are those composed of 34-26 mole %,
especially 33-27 mole %, particularly 32-28 mole %, more especially
31-29 mole %, and particularly preferably 30 mole % of monomer
corresponding to formula (I), in each case supplemented by a
complementary proportion of monomer corresponding to formula
(II).
The percentage of monomers is defined based on 100 mole %
representing the whole content of Bisphenols in the polycarbonate.
A pure Bisphenol A Polycarbonate would therefore be defined as 100
mole % of Bisphenol A. The carbonate Part of derived from carbonic
acid esters or halides is not taken into account.
Copolycarbonates which are preferred, particularly preferred or
most preferred are those containing the compositions defined under
preferred, particularly preferred or most preferred.
The general definitions, quantitative ratios or connotations stated
above or those stated in preferred ranges, can however also be
combined with each other in any desired manner, i.e. from among the
respective ranges and preferred ranges. They apply correspondingly
to the end products and to the precursors and intermediates.
Surprisingly, it has now become apparent that these
copolycarbonates have particularly good low temperature properties
and good impact behaviour after heat ageing. They may therefore be
used as moulded articles in all applications where the
polycarbonates known hitherto are inadequate in terms of their
range of properties, particularly, e.g., in the electrical sector
and in the construction sector, for coverings or glazing,
particularly in the automotive sector as films, sheets, fittings
parts or housing parts, and in the optical sector as lenses and
data stores, and as consumer goods, namely in cases where increased
heat resistance or chemical resistance is required at the same time
as good low temperature properties. In addition, they may also
replace other materials in which conventional polycarbonates could
not be used hitherto because of their inadequate low temperature
properties for said purpose.
According to the invention, the term good low temperature
properties means, by way of example but not in a restrictive
manner, good low temperature notched impact strength, since
conventional polycarbonates become brittle at low temperatures and
thus have a tendency to fracture and crack.
According to the invention, the term low temperatures means
temperatures below 0.degree. C., preferably below -10.degree. C.,
particularly preferably below -20.degree. C., more particularly
preferably below -30.degree. C., particularly below -40.degree. C.
and preferably below -50.degree. C.
According to the invention high thermal stability is understood to
be, by way of example and not limitation, high notched impact
strength after tempering, since commonly available polycarbonates
become brittle after tempering and thus tend to fracture and
tear.
According to the invention tempering is understood to be storage at
temperatures below the glass transition temperature of about
155.degree. C., preferably between 40 and 140.degree. C.,
particularly preferably 60-140.degree. C., most particularly
preferably 80-140.degree. C.
Preferred compounds corresponding to formula (I) are
4,4'-dihydroxydiphenyl (DOD) and
4,4'-dihydroxy-3,3',5,5'-tetra(tert.-butyl)diphenyl,
4,4'-Dihydroxy-3,3',5,5'tetra(n-butyl)diphenyl and
4,4'-dihydroxy-3,3',5,5'tetra(methyl)diphenyl, particularly
4,4'-dihydroxydiphenyl.
Preferred compounds corresponding to formula (II) are
2,2-bis(4-hydroxyphenyl)propane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
1,1-bis(4-hydroxyphenyl)-cyclohexane, preferably
2,2-bis(4-hydroxyphenyl)propane (bisphenol A) and
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexan (bisphenol TMC),
particularly preferably 2,2-Bis(4-hydroxyphenyl)propan (bisphenol
A).
It is possible to use both one compound corresponding to formula
(I), with the formation of binary copolycarbonates, and several
compounds corresponding to formula (I).
It is also possible to use both one compound corresponding to
formula (II), with the formation of binary copolycarbonates, and
several compounds corresponding to formula (II).
The starting products corresponding to formula (I) and (II) may of
course contain impurities due to the synthesis. High purity is
desirable, however, and should be sought, so these starting
products are using in the highest possible purity.
Processes for production of Polycarbonates an Copolycarbonates are
well-known in the literature and are applied to the Polycarbonates
and Copolycarbonates according to the invention.
According to DE-OS 2 119 779, the preparation of polycarbonates
takes place with the participation of monomers corresponding to
formula (I) preferably in solution, namely by the interfacial
process and the homogeneous phase process.
For the preparation of polycarbonates by the interfacial process,
reference is made by way of example to "Schnell", Chemistry and
Physics of Polycarbonates, Polymer Reviews, Vol. 9, Interscience
Publishers, New York, London, Sydney 1964 and to Polymer Reviews,
Volume 10, "Condensation Polymers by Interfacial and Solution
Methods", Paul W. Morgan, Interscience Publishers, New York 1965,
Chapter VIII, p. 325 and EP 971 790.
In addition, the preparation may also be carried out by the well
known polycarbonate preparation process in the melt (known as the
melt transesterification process) which is described, e.g., in
DE-OS 19 64 6401 or in DE-OS 1 42 38 123. In addition,
transesterification processes (acetate process and phenyl ester
process) are described, for example, in U.S. Pat. Nos. 3,494,885,
4,386,186, 4,661,580, 4,680,371 and 4,680,372, in EP-A 26 120, 26
121, 26 684, 28 030, 39 845, 91 602, 97 970, 79 075, 146, 887, 156
103, 234 913 and 240 301 and in DE-A 1 495 626 and 2 232 997.
The polycarbonates according to the invention possess molecular
weights (Mw, weight average) of 10.000 to 60.000, preferably of
20.000 to 55.000, determined by measuring the relative solution
viscosity in Dichloromethane or in 50:50 mixtures of
Phenol/o-Dichlorobenzene, calibrated by the light scattering
method.
The polycarbonates according to the invention are melt processable
in the usual way at temperatures from 240.degree. C. to 380.degree.
C., preferably from 260.degree. C. to 360.degree. C. Any moulded
and extruded articles and films may be prepared in the known way by
injection moulding or by extrusion.
Such moulded and extruded articles are also subject matter of the
present invention.
The polycarbonates according to the invention are freely soluble in
solvents such as chlorinated hydrocarbons, e.g., methylene
chloride, and may thus be processed, for example, in the known way
to cast films.
The combination of properties such as heat resistance, good low
temperature properties in combination with good impact behavior
after heat aging and resistance to chemicals permits a wide use of
the copolymers according to the invention. Potential applications
for the polycarbonates according to the invention include: 1.
Safety screens/windows, which are known to be required in many
parts of buildings, vehicles and airplanes, as well as shields for
helmets. 2. Production of films, and in particular films and thin
sheet layers for skis. 3. Production of blow molded hollow body
parts (see for example U.S. Pat. No. 2,964,794), such as for
example 1- to 5-gallon water bottles. 4. Production of transparent
sheets, and in particular multi-wall sheets, such as for example
for covering buildings such as railway stations, greenhouses and
lighting installations. 5. Production of optical data storage
media. 6. For the production of traffic light housings or road
signs. 7. For the production of foams (see for example DE-AS 1 031
507). 8. For the production of filaments and wires (see for example
DE-AS 1 137 167 and DE-OS 1 785 137). 9. As translucent plastics
containing glass fibres for lighting purposes (see for example
DE-OS 1 554 020). 10. As translucent plastics containing barium
sulphate, titanium dioxide and/or zirconium oxide or organic
polymeric acrylate rubbers (EP 634 445, EP 269 324) for the
production of transparent and light-scattering parts. 11. For the
production of precision injection-molded parts, such as for lens
holders. For this purpuose polycarbonates are used with a content
of glass fibers which optionally additionally contain about 1-10
wt. % of MoS.sub.2, based on the total weight. 12. For the
production of optical parts of devices, and in particularly lenses
for cameras (see for example DE-OS 2 701 173). 13. As light
transmission carriers, and in particularly as light pipes (see, for
example EP-A1 0 089 801). 14. As electrically insulating materials
for electrical conductors and for plug casings and plug-and-socket
connectors. 15. Production of mobile telephone housings with
improved resistance to perfumes, after-shaves and perspiration. 16.
Network interface devices. 17. As a carrier material for organic
photoconductors. 18. For the production of lighting lenses, such as
for example automotive headlight lamps, diffusing screens or
interior bulb cap lenses, spot light lenses and general lighting
lenses. 19. For medical applications, such as for example
oxygenators, dialyzers. 20. For food applications, such as for
example bottles, tableware and chocolate moulds. 21. For
applications in the automobile sector, where contact with fuels and
lubricants can occur, such as for example for bumpers, optionally
in the form of suitable blends with ABS or suitable rubbers. 22.
For sports articles, such as for example slalom poles snow boards
and ski shoe bindings. 23. For household articles, such as for
example for kitchen sinks and postbox housings. 24. For housings
such as for example electrical enclosures. 25. Casings for electric
toothbrushes and hair-drier housings. 26. Transparent washing
machine doors with improved resistance to the washing liquid. 27.
Safety goggles, optical correction glasses. 28. Lamp covers for
kitchen installations having improved resistance to kitchen vapors,
an in particular oil vapors. 29. Packaging films for medications.
30. Chip boxes and chip carrier trays. 31. For other applications,
such as for example for stable doors or animal cages.
In particular, films may be produced from the high molecular weight
aromatic polycarbonates of the invention. The films have preferred
thicknesses from 1 .mu.m to 1500 .mu.m, particularly preferred
thicknesses from 10 .mu.m to 900 .mu.m.
The films obtained may be monoaxially or biaxially oriented in an
inherently known way, preferably in a ratio of 1:1.5 to 1:5.
The films may be produced by the known methods for film production,
e.g., by extrusion of a polymer melt through a flat film die, by
blowing on a film blowing machine, by thermoforming or casting. It
is possible for the films to be used on their own. They may also,
of course, be used to produce composite films with other plastics
films by the conventional methods; in principle, depending on the
desired application and final property of the composite film, all
the known films are suitable as partners. A composite of two or
more films may be produced.
In addition, the copolycarbonates according to the invention may
also be used in other layer systems, such as, e.g., in coextruded
sheets.
The polycarbonates according to the invention may contain various
terminal groups. These are introduced by chain terminators. Chain
terminators within the meaning of the invention are those
corresponding to formula (III) ##STR3##
wherein R, R' and R", independently of one another, may represent
H, optionally branched C.sub.1 -C.sub.34 -alkyl/cycloalkyl, C.sub.7
-C.sub.34 -alkaryl or C.sub.6 -C.sub.34 -aryl, for example, butyl
phenol, trityl phenol, cumyl phenol, phenol, octyl phenol,
preferably butyl phenol or phenol.
The polycarbonates may contain small amounts from 0.02 mole % to
3.6 mole % (based on the dihydroxy compound) of branching agents.
Suitable branching agents include the compounds having three and
more functional groups suitable for polycarbonate production,
preferably those having three or more than three phenolic OH
groups, for example, 1,1,1-tri-(4-hydroxyphenyl)ethane and isatin
biscresol.
In order to alter the properties, auxiliaries and reinforcing
agents may be added to the polycarbonates according to the
invention. Suitable agents of this kind include, inter alia: heat
and UV stabilisers, flow promoters, mould release agents, flame
retardants, pigments, finely divided minerals, fibrous materials
e.g., alkyl and aryl phosphites, phosphates, phosphanes, low
molecular weight carboxylates, halogen compounds, salts, chalk,
quartz flour, glass fibres and carbon fibres, pigments and
combinations thereof. Such compounds are described, e.g., in WO
99/55772, p. 15-25, and in "Plastics Additives", R. Gachter and H.
Muller, Hanser Publishers 1983.
Moreover, other polymers may also be added to the polycarbonates
according to the invention, e.g., polyolefins, polyurethanes,
polyesters, acrylonitrile butadiene styrene and polystyrene.
These substances are added preferably to the finished polycarbonate
in conventional machines, but they may also be added at another
stage of the production process, depending on requirements.
The examples below are intended to illustrate the present invention
but without limiting its scope.
EXAMPLES
Various polycarbonates were synthesised by the known methods of
preparation in the melt, as described, for example, in DE 4 238 123
and by the interfacial method, as described, for example, in
"Schnell", Chemistry and Physics of Polycarbonates, Polymer
Reviews, Vol. 9, Interscience Publishers, New York, London, Sydney
1964, and compared with commercial Makrolon with comparable
viscosity.
The relative solution viscosity was determined in dichloromethane
in a concentration of 5 g/l at 25.degree. C., calibrated by the
light scattering method
tert.-Butylphenol was in all cases used as a chain terminator
within the interfacial process, no extra chain terminator was
applied using the melt transesterification process.
The flexural impact test to ISO 180/4A was used to determine the
impact resistance.
Example 1
A polycarbonate with 30 mole % of dihydroxydiphenyl (DOD) and 70
mole % of bisphenol A was prepared by the interfacial process. The
granules had a relative solution viscosity of 1.298.
Example 2
A polycarbonate with 30 mole % of DOD and 70 mole % of bisphenol A
was prepared by the interfacial process. The granules had a
relative solution viscosity of 1.341.
Example 3
A polycarbonate with 30 mole % of DOD and 70 mole % of bisphenol A
was prepared by the melt transesterification process. The product
had a relative solution viscosity of 1.28.
Comparison Example 1
A polycarbonate with 35 mole % of DOD and 65 mole % of bisphenol A
was prepared by the melt transesterification process. The product
had a relative solution viscosity of 1.295.
Comparison Example 2
A polycarbonate with 25 mole % of DOD and 75 mole % of bisphenol A
was prepared by the melt transesterification process. The product
had a relative solution viscosity of 1.295.
Comparison Example 3
A polycarbonate with 20 mole % of DOD and 80 mole % of bisphenol A
was prepared by the melt transesterification process. The product
had a relative solution viscosity of 1.295.
Tables 1-2 show a comparison with commercial Makrolon.
TABLE 1 Comparison of solution viscosities Polycarbonate Relative
solution viscosity Makrolon 2808/58 1.293 Makrolon 3108 1.318
Example 1 1.298 Example 2 1.341 Example 3 1.277 Comparison example
1 1.295 Comparison example 2 1.298 Comparison example 3 1.286
TABLE 2 Comparison of notched impact resistance and softening point
Notched impact test to ISO 180/4A -40.degree. C. -50.degree. C.
-60.degree. C. Polycarbonate 23.degree. C. [kJ/m.sup.2 ]
[kJ/m.sup.2 ] [kJ/m.sup.2 ] [kJ/m.sup.2 ] Makrolon 2808/58 90z 8s
9s 7s Makrolon 3108 95z 11s 8s 8s Example 1 82z 56z 58z 60z Example
2 67z 67z 65z 66z Example 3 54z 60z 38z 42z Comparison ex. 1 Not
35z 26s 20s determined Comparison ex. 2 Not 19s Not 13s determined
determined Comparison ex. 3 Not 14s Not 11s determined determined s
= brittle fracture z = ductile fracture
Table 2 shows the superior low temperature strength of the
copolycarbonates according to the invention of Examples 1-3 at
-60.degree. C.
TABLE 3 Comparison of the notched impact strengths according to ISO
180/4A in [kJ/m.sup.2 ] Conditions of storage with tempering
Example 1 Makrolon 2808 46 h at 135.degree. C. 52z 8s 7 d at
135.degree. C. 54z 20 d at 135.degree. C. 52z 2 h at 150.degree. C.
53z 24 h at 150.degree. C. 53z s = brittle fracture z = ductile
fracture
As shown in table 3 the copolycarbonate according to the invention
has a markedly unchanged property profile even after ageing. After
a storage period of only 46 hours at 135.degree. C. the
polycarbonate of pure bisphenol A displays brittle fracture
properties whereas the ductile properties of the copolycarbonate
can still be observed even after 7 days. In addition, even when
stored at 150.degree. C. followed by an examination of notched
impact strength the copolymer displays high level ductile fracture
properties.
* * * * *